T7 RNA Polymerase from bacteriophage T7. Modified T7 RNA Polymerase with higher tolerance towards modified nucleotides. Extremely useful for radioactive and non radioactive labeling as well as for RNA synthesis for preparive scale. DNA-dependent RNA polymerase which has stringent specificity for T7 phage promoters sequence. Efficiently synthesizes in vitro transcripts from almost any DNA that is downstream from a T7 promoter. Suitable for preparing labeled single-stranded RNA probes of high specific activity. Transcripts can be used as hybridization probes, templates for in vitro translation, substrates in RNA processing systems, or exon and intron mapping of genomic DNA.